This invention relates to ink jet recording apparatus, particularly to ink jet recording apparatus having means suitable to indicate disorder by recording.
Ink jet recording apparatus has been developed such that when an ink particle is separated from an ink plume jetted under pressure from a nozzle, the ink particle is charged by a charging electrode provided in a region where the ink particles are to be separated from the ink plume. The separation of ink particles must be synchronized with a charging phase applied to the charging electrode in accordance with recording signals. Without such synchronizing relation, the charging magnitude of ink particle does not correspond to the magnitude of recording signals, which results in a failure to obtain the deflection desired. In order to make separation of ink particles stable, the nozzle is mechanically vibrated and the phase of separation of the ink particle is matched for one of the vibrations of the nozzle, but the separation of the ink particle may widely deviate from the phase of the vibration of the nozzle, because of change of viscosity of ink particles, pressure applied to the ink, or violency of mechanical vibration of the nozzle. In such a case, some ink particles can not be charged, as a result some ink particles cannot reach a predetermined position of recording medium and thereby cause disorder in recording.
When the record is disturbed, it is desirable that the portions of the apparatus causing the unstable condition be corrected after the operation of the apparatus is stopped. However in some cases where the recording is in disorder, no recording is provided on the recording medium, whereas in some other uses, a recording with small amounts of disorder in the recording is obtained. In the former case, the condition of recording can be detected by a photo reader, but in the later case that the record is left on the recording medium but has therein a portion of the recording disorder, the apparatus for detection becomes complicated in its construction and of high cost.
Further it is desirable to indicate or provide information of a recording disorder before it appears actually, visually on the recording medium.